DE1521065C3 - Acid galvanic nickel bath for the deposition of decorative fine-grained, satin to high-gloss coatings with improved corrosion resistance - Google Patents

Description

3 4

Coating, if you want the usual thin final 1 to 20 g / l barium sulfate or strontium sulfate Chrome plating of approximately 0.25 microns is applied to the bath. Mixtures of fine silica will. Improved protection against corrosion is also obtained even with cerium oxalates and / or magnetite with the decorative coatings (with an ab- very good results, and the most favorable results A final chrome coating of a thickness of less than 5 is obtained at concentrations of 20 to 50 g / l than about 5 microns) obtained from baths containing only silica and 5 to 50 g / l magnetic iron oxide. Rental wa Contains 0.5 g / l oxalate particles. The oxalates of cerium oxalates and oxalates of the rare ones In the case of lower concentrations, powders tend to be earths with magnetite powder giving very good results than, for example, the oxides. Nits, especially with 1 to 20 g / l oxalates, are less common

The greatest possible improvement in corrosive earth to 5 to 50 g / l magnetic iron oxide, protection of the less easily accessible exempt thorium fluoride when used alone as solid areas of the objects is achieved if, for example, material in high and semi-gloss nickel baths allows 10 to 100 g / The one-part solids are dispersed in the nickel coating with a similarly high corrosion resistance bath. A further increase in speed after chrome plating, as it does when using the concentration, does not improve that which is already achieved from the oxalate. Even when using drawn corrosion resistance, if a. ab- Thorium fluorate is applied alone or in a mixture with a thin chrome coating. Thorium tetrafluoride or thorium fluosilicate as solid coatings, which are obtained from baths, which materials are good results. When used, higher solids concentrations are caused in shiny nickel baths, however, Magnebis to a point where another ao tit powder produces a much greater turbidity in the coating, an increase in the concentration does not result in any further loss but a coating of superior Corrosion change in the appearance of the nickel coating with sion resistance. A glossy coating takes place with given working conditions. Lowest turbidity and excellent corrosion protection properties is achieved with microfine silica in a mixture with other fine non-metallic and acid powders at a concentration of 40 to -50 g / l in the bath insoluble powders of an average in the high-gloss nickel baths. As mentioned, given particle sizes of about 5 microns and less, combinations of solids can also be used successfully, e.g. B. Mixtures of nickel-rich can be used. The addition of thorium oxalate powder with fine silica powder, fine fluoride in an amount of 1 to 10 g / l, magnetite with nickel carbonate powder or fine calcium fluoride - 30 0.5 g / l and cerium oxalate at 1 to 10 g / l with 40 to 50 g / l powder. Excellent combinations of fine solids Silicic acid in the bath enables one to achieve a are nickel oxalate and silicon dioxide, with or without a fine grain coating, which is then coated with barium oxalate, strontium oxalate or strontium sulfate. Chromium less than 5 microns thick- These mixtures are best prepared in the following way, with an excellent corrosion resistance: A solution of sodium is obtained, especially when the fine-grained oxalate, magnesium oxalate or oxalic acid (1% until coating is applied over a semi-glossy and / or high-saturation) of a porous silicon dioxide powder glossy nickel coating, absorbed, preferably Philadelphia quartz, a In the following examples, the lower solid microfine silica, or a silica concentration of about 0.5 g / l to about 50 g / l similar powder, which has a maximum particle 40 best for high-gloss coatings of a gloss size of 0.02 microns, but is generally suitable for nickel baths and can thus be conveniently used in agglomerated form of capsules of about for thin Coatings of about 0.25 to about 5 microns, 1.5 microns average particle size are present. Thickness above a usual shiny or semi-glossy ^: ·) The excess liquid from the siliceous nickel coating is used to drain acid powder, and the latter is added to the 45 after the subsequent thin chrome coating high or semi-gloss nickel bath. The silica a highly corrosion-resistant gloss coating to acid is not only beneficial and effective in achieving it. Accelerated corrosion tests of the formation of the decorative fine-grained coating using the CASS and Corrodkote were involved, but also modified the formation and prescriptions were carried out, and the normal growth of nickel oxalate precipitates was carried out. If the 5 ° high and semi-gloss nickel coatings of only 15 or silica with barium or strontium chloride im- 20 microns under a thin coating of for example impregnated and then mixed with nickel oxalate powder, 0.25 to 2.5 microns thick from the in or impregnated with sodium oxalate and then added to the baths described in the following examples and a high-gloss bath, excellent results in terms of corrosion resistance will be passed through many cycles. In contrast, have achieved speed when the excess gained from the bath. Plating with the usual bright nickel which is given a chrome plating of less than 5 microns of the same total plating thickness and the same thickness. Other commercially available final thin chromium plating survived a single fine silica in the form of agglomerates of cycle.

Average particle sizes of at least 5 microns, 60 The following examples illustrate the invention, which have the tendency in moving baths in

Agglomerates about 1.5 microns in size to break apart the II also give satisfactory results. A solid mixture of silica, nickel- The bath was moved through air oxalate or without barium or strontium sulfate an average particle size of 65 g / l of 5 microns and less nickel oxalate (average Parger bring optimal results when 10 to 50 g / l particle size , 5 microns and less) 10 to 100 fine silica, 0.5 to 20 g / l nickel oxalate and NiSO ₄ · _{6H 2} O 200 to 300

NiCl ₂ · 6 H ₂ O 40 bis

H ₃ BO ₃

o-Benzoyl sulfimide 1 bis

p-toluenesulfonamide 1 bis

Allylsulfonic acid 1 bis

2-butynoxy-1,4-diethanesulfonic acid 0.05 to 0.2

pH = 3.5 to 5.5, bath temperature 50 to 70 ⁰ C.

Example II

The bath can be moved by air or mechanically

g / l

Nickel oxalate 1 bis

Silica powder 30 to

NiSO ₄ · 6 H ₂ O 200 to

NiCl ₂ -OH ₂ O 40 bis

H ₃ BO ₃

Benzenesulfonamide 2 bis

Allylsulfonic acid 1 bis

N-allyl quinaldine bromide 0.003 to 0.01

pH 4 to 6; Temperature 50 to 70 ° C.

Example III Air Movement

g / i

Rare earth oxides (average particle size, 5 microns and less) 0.5 to

Cerium oxalate (average particle size, 5 microns and less) 0.5 to

NiSO ₄ · 6 H ₂ O 200 to

NiCl ₂ -OH ₂ O 40 bis

H ₃ BO ₃

o-Benzoyl sulfimide 1 bis

Benzenesulfonamide 1 bis

Allylsulfonic acid 1 bis

2-butynoxyl, 4-diethanesulfonic acid 0.05 to 0.2

pH 3.5 to 5.2; Bath temperature 50 to 70 ° C.

Example IV Air movement or mechanical movement

g / l

Cerium oxalate (average particle size, 5 microns and less) 0.5 to

NiSO ₄ · 6 H ₂ O 200 to

NiCl ₂ -OH ₂ O 30 bis

H ₃ BO ₃ bromal and / or chloral hydrate 0.05 to 0.1

Formaldehyde 0.02 to 0.08

pH 3.5 to 5.2; Bath temperature 45 to 65 ° C.

Example VI

Air movement for workpieces on racks, mechanical movement for electroplating in drums

g / l

Magnetite (average particle size, 5 microns and less) 0.5 to 5.0

ίο Silica (about 0.015 microns, outermost particle size and average Particle size of the agglomerates, 1.5 microns) 40 to 50

NiSO ₄ · 6 H ₂ O 100 bis

NiCl ₂ -OH ₂ O 40 bis

H ₃ BO ₃ 40

o-Benzoyl sulfimide 1 to 4

Benzenesulfonamide 1 to 2

Allylsulfonic acid 1 to 4

2-butynoxy-1,4-diethanesulfonic acid 0.05 to 0.2

pH 3.5 to 5.2; Bath temperature 50 to 70 ° C.

Example VII - air movement

Example V air movement

Lanthanum oxalate or neodymium oxalate or oxalate (average Particle size 5 microns and

fewer)

Magnetite

NiSO ₄ · 6 H ₂ O

NiCl ₂ · _{6H 2} O

H ₃ BO ₃

o-benzoyl sulfimide

Benzenesulfonamide

Allyl sulfonic acid

2-butynoxyl, 4-diethansulfonic acid pH 3.5 to 5.2; Bath temperature 50

g / l

g / l

Didymium oxide 1 to 10

Rare earth oxalate (average particle size, 5 microns and less) 1 to 50

NiSO ₄ -OH ₂ O 0 to 50

NiCl ₂ · 6 H ₂ O 150 bis

H ₃ BO ₃ 40

Nickel succinate 0 to 15

o-Benzoyl sulfimide 1 to 4

Benzenesulfonamide 1 to 2

Allylsulfonic acid 1 to 4

2-butynoxy-1,4-diethansulfonic acid 0.05 to 0.2.,

pH 3.5 to 5.2; Bath temperature 50 to 70 ° C.

Example VIII Air movement

g / l

0 , 5 to 50 up to 300 0.5 to 50 6o to 120 200 40 to 4 40 to 2 65 1 to 4 1 0.05 to 0.2 1 70 ° C. until

Thorium fluoride alone and / or mixed with thorium fluorate, thorium fluorosilicate, thorium fluoaluminate, Thorium fluotitanate and thorium fluozirconate (average particle size, 5 microns and less) 1 to 50

NiSO ₄ · 6 H ₂ O 150 to

NiCl ₂ · 6 H ₂ O 150 to 50

H ₃ BO ₃

40

o-Benzoyl sulfimide 1 to 4

Benzenesulfonamide 1 to 2

Allylsulfonic acid 1 to 4

2-butynoxy-1,4-diethansulfonic acid 0 ^ 05 to 0.2

pH 3.5 to 5.2; Bath temperature 50 to 70 ° C.

Claims (6)

1 2 claims:. ? s for galvanic nickel bath of the invention is characterized in that it is a one-piece solid 1. Acid galvanic nickel bath to the waste an oxalate of nickel, cobalt, manganese, yttrium, sheath decorative fine-grained, satin to high-scandium or a rare earth metal; one shiny coatings with improved corrosion 5 phosphate, fluoride, silicide or phosphide of a metal strength, if necessary for applying one of the rare earths; an oxide, silicate, titanate, stannate further galvanic coating, which in addition to or zirconate of yttrium, lanthanum, neodymium, soluble, organic brighteners in addition to praseodymium, samarium, didymium or an unextended one 10 to 500, in particular 50 to 200 g / l separated mixture of rare earths; one in the bathroom dispersed, finely divided, semi-conductive or non-conductive io insoluble ferrite or chromite or one in the bath inert inorganic solids with a completely insoluble compound of a metal of the actinide cut Particle diameter below 5 μ, foremost with the exception of an oxide, phosphate, oxa, in some cases contains less than 2 μ, in particular between 0.02 lat or stannate of thorium. and 0.5 µ contains, according to main patent 1,248,413, of the above-mentioned oxalates, the transition thereby characterized that it is classified as 15 metals, ferrites, chromites, the compounds of finely divided solid an oxalate of nickel, rare earth metals and the compounds of actini cobalt, Manganese, yttrium, scandium or any of the series including thorium tetrafluoride, thorium metal of the rare earths; a phosphate, fluoride, fluoborate, thorium fluosilicate, thorium sulfide, thori-silicide or sulfide of a rare earth metal; umsilicate, (thorite) thorium titanate, thorium zirconate, an oxide, silicate, titanate, stannate or zirconate 20 uranium tetrafluoride, and the uranium sulfides · give of yttrium, lanthanum, neodymium, praseodymium, in general the oxalates give the best results, Samarium, Didym or an unseparated bowl if they are in high or semi-gloss nickel baths on the mix of rare earths; a base of nickel chloride, bromide and sulphate, which is insoluble in the bath, Ferrite or chromite or a fluoride, fluoroborate, sulfamate or benzene-Me compound that is insoluble in the bath a metal of the actinide series, 25 than, or ethanesulfonate can be used. Nickel with Except for an oxide, phosphate, oxalate oxolaf powder gives excellent results in terms of or stannate of thorium. on a very high level of corrosion protection «The nickel 2. Bath according to claim 1, characterized in that oxalate particles can be used as precipitates directly in the records that it can be formed as a finely divided solid in the bath by soluble oxalates such as Bath insoluble silicate, fluoride, fluoborate, fluo- 30 sodium, potassium, lithium or magnesium oxalate silicate, fluotitanate, fluozirconate, fluoaluminate or oxalic acid itself can be added, and can or sulfide of a metal of the actinide series, obtained by movement in a bath, preferably air. . movement, easily dispersed in it. Of these 3. 'Bath according to claim 1, characterized in that soluble oxalates are sodium and magnesium, that it is a finely divided solid an oxalate for the direct formation of nickel oxalates Contains stannate, oxalate or oxide of uranium. preferred. Bring oxalates of cobalt and manganese 4. Bath according to claim 1, characterized also good results. Extremely satisfying draws that it as a finely divided solid in the bath results are also with oxalates of the rare ones insoluble nickel, cobalt, manganese, gadolini earths from very low to very high concentration, Iron-cobalt or iron (II) ferrite; iron (II) -, 40 trations achieved in the bath. Cerium oxalate powder is very good, Barium, nickel or cobalt chromite; Thorium as well as a mixed "oxalate of rare earths", Tetrafluoride, -fluoborate, -fluosilicate, -sulfide, -silicate, Other are relatively cheap oxalates of rare earths -fluoaluminate, -fluotitanate or -fluozirconate; or neodymium, didymium (a natural mixture of Contains uranium tetrafluoride or sulphide. Neodymium and praseodymium). Yttrium and lanthanum 5. Dip after any of the previous 45 oxalates are not overly expensive in technical Claims, characterized in that they are approximately pure and give excellent results. 0.5 to 300, preferably 0.5 to 50 g / l of the fine scandium oxalate and the oxalates of the rare earths Partial solid contains. Samarium, Gadolinium, and Praseodynium all give birth 6. Bath after any of the preceding also good results, however these are oxalates Claims, characterized in that it is currently significantly more expensive than cerium oxalate 50; Lanthanum about 1 to about 50 g / l of a finely divided or neodymium oxalate, europium, terbium, dyspro silicon dioxide an average particle sium, erbium, holmium, ytterbium, thulium, diameter less than 5 microns. and lutetium oxalates are isolated and very expensive are therefore less preferred than the substances 55 which are technically pure as oxalates Earth «, cerium oxalates, lanthanum oxalates, neodymium oxalates The invention relates to an acidic galvanic laten and didymium oxalates available commercially Nickel bath for the deposition of decorative fine-grained. Many of these oxalates, such as cerium oxalate and cobalt satin to high-gloss coatings with improved oxalates also form certain nickel oxalates than fine ones Corrosion resistance, possibly for the deposit, if added to the nickel baths bring another galvanic coating, wel-. The nickel oxalate and the other water In addition to soluble, organic brighteners to insoluble oxalates are at least in the nickel additives preferably 10 to 500, in particular 50 to baths with higher pH values, such as. B. with pH-g / l dispersed, finely divided, half or non-values from 4 to 6, soluble. conductive inert inorganic solids with a 65 coating, which from baths with these oxalate depressants average particle diameter below 5 μ, whipping and powders are obtained, in particular preferably below 2 μ, in particular between 0.02 with nickel oxalate and oxalates of the rare earths, and 0.5 μ contains, according to German patent specification 1 248413 result in an exceptionally corrosion-resistant